1. Field of the Invention
This invention relates to a valve apparatus, in particular to a proportionally-acting electromagnetic valve, in accordance with aspects of the invention to be discussed below.
2. Background Information
German Patent No. 29 34 181 essentially discloses a valve apparatus such as that to which the present invention generally relates. In the valve apparatus disclosed therein, a valve housing contains a first valve seat which, together with a first valve body, forms a first valve, and a second valve seat which, together with a second valve body, forms a second valve. The first and second valves are located coaxially behind one another. The first valve body and the second valve body are located on a tappet which is used for the joint activation of both valves.
For the first valve, there is a first pressure medium inlet chamber, and for the second valve there is a second pressure medium inlet chamber. Additionally, there is a pressure medium outlet chamber, which can be connected simultaneously by means of the first valve and the second valve to the first pressure medium inlet chamber and the second pressure medium inlet chamber, or can be shut off from them.
As a result of the configuration of two pressure medium inlet chambers, which can be connected simultaneously by means of both valves to the pressure medium output chamber, it is generally possible to release large flow cross sections with small movements of the valve bodies. However, a disadvantage with this known configuration, in which two valve bodies are rigidly connected to one another, may be found in that it is possible that one of the two valve bodies may not be seated exactly on its corresponding valve seat, possibly, for example, on account of manufacturing tolerances. As a result, leaks may occur.